An Attribute Certificate is for certifying what kind of attribute a person has as a user authority, in contrast to a usual private key certificate, which is for certifying identification of a person. The specification of an Attribute Certificate is defined in X.509 stipulated by IETF (Internet Engineering Task Force) (for example, see Non-Patent Document 1). An Attribute Certificate is issued not by the Certification Authority, which issues a private key certificate, but by the Attribute Authority. The standard of OASIS (Organization for the Advancement of Structured Information Standards), SAML (Security Assertion Markup Language) has also been separating the certificate of identification and the certificate of attribute. This enables flexible certification and authorization to be given across domains of independent authorities. This also led a proposal of a new certificate service called the Federated ID (for example, see Non-Patent Document 2).
This attribute information (attribute data) includes name, street address, age, occupation, telephone number, sex, family structure and the like, varying from what relating to the position in the organization certified by the personal department of a company to individual interests or the like. The abovementioned attribute certificate is only available where the attribute can be certified by a public third party. A third party authority is not suitable as an authority for a personal attribute such as individual interests in terms of privacy protection. As such, the attribute is divided into the Authorized attribute certified by a third party and the Discretionary attribute defined totally by individual discretion, both of which have different security requirements.
A conventional art is for enabling additional information to be disclosed concurrently when a payment is made by credit at a store by storing attribute information including street address and the like as well as the card number in the IC-chip credit card in order to treat attribute data as credit information (for example, see Patent-Document 1). The Patent-Document 1 also describes a function of controlling information to be disclosed according to a disclosure level of the information by classifying the additional information. The Patent-Document 1 also describes a function of having a credit center run by a credit company or the like to rank the credit level of each franchisee and deciding information disclosure level according the rank.
A technique has been disclosed for simplifying input operation of personal information needed for a person to purchase a product or receive a service via a network, by making an authorizing server to issue a universal ID, which is a common ID, to a new registrant, retrieve necessary information for the business transaction including street address and the like from the registrant's personal information and send the information to another terminal in response to a requirement made when this universal ID is presented, in an authorizing system for a communication via a network (for example, see Patent-Document 2).    [Non-Patent Document 1]: FC3281 on An Internet Attribute Certificate [searched on Aug. 4, 2003] Internet    [Non-Patent Document 2]: Liberty Alliance [searched on Aug. 4, 2003] Internet    [Patent Document 1]: Japanese Patent Publication No. 2001-325526 (pp. 4-5, FIG. 1)    [Patent Document 2]: Japanese Patent Publication No. 2001-244927 (pp. 3-4, FIG. 1)
If the information shared by a person and a service provider, which services the person, including a bank account, a purchase history and membership information among the abovementioned Authorized attribute is also treated as the person's attributes, it would be convenient in many respects. In the United States, examination performed for authorizing a card is quite strict, requiring a transaction history to prove that the applicant has maintained a bank account for more than a year, for example. If the bank certifies such a fact for such an occasion, a new business transaction can be opened more easily, which can be a favorable service for both an applicant and a service provider. Such shared information basically should be protected as personal information, however, a system of personal attribute credit service, which enables such information to be certified by a service provider protecting the information in response to the person's assent and need, is desired. Credit card business is a typical business for servicing credit. With this business, in which the object of the credit is the money up to the credit amount, a card member of a credit card company receives settlement service for a commodity purchased at the company's affiliated store. On a network such as the Internet, however, parties who know nothing about each other want to open a business transaction with each other. Features of the credit over a network include:
1. that the object of credit must be confidence information other than money, and
2. that the parties want to open a business transaction with each other need not belong to the same confidence authority. Therefore, a membership of a reliable organization, the period of the membership, and the history of the person's activity during the period play an important roll as credit other than money, which cannot be realized in a credit card system. All of them are information shared by the person and the organization, to which the person belongs. In order to develop a confidence, the two parties that want to open business with each other need not belong to the same organization. A system for enabling a party to determine confidence of the counterpart in view of the party's criterion is needed. In the credit card system of these days, where accountability, a credit limit and a transaction object are predetermined, a system for providing such flexible credit, which is desired on the network, has not been realized yet.
In the technique described in the abovementioned Patent Document 1, the participants are limited to those within the conventional credit card scheme and the attributes of the participants are limited to information needed by a store to deliver a commodity. Techniques for certifying an attribute like the abovementioned X.509 do not cover a specific service system, such that the technique described in Non-Patent Document 1, for example, only defines a format of an attribute certification. In the technique described in the abovementioned Patent-Document 2, a subscriber cannot control such things as anonymity of the subscriber or what kind of attribute is to be certified. The subscriber does not get sufficient protection of the privacy, as a personal information handling agent always recognizes the new trader, with whom the subscriber wants to carry on a business transaction.
The present invention is adapted to solve the abovementioned technical problems. The object of the present invention is to realize an attribute information providing service for enabling an attribute other than money, for example, to be an object of credit by using a network such as the Internet.
Another object of the present invention is to provide a part of subscriber's personal information to the new trader with the approval of the subscriber.
Yet another object of the present invention is to enable authorization without letting a personal information handling agent to know the new trader, with whom the subscriber wants to carry on a business transaction.